Acute Stress Group Research Articles

Dexmedetomidine affects the NOX4/Nrf2 pathway to improve renal antioxidant capacity.

The study aimed to investigate the protective effects of dexmedetomidine (DEX) on renal injury caused by acute stress in rats and explore the protective pathways of DEX on rat kidneys in terms of oxidative stress. An acute restraint stress model was utilized, where rats were restrained for 3 hours after a 15-minute swim. Biochemical tests and histopathological sections were conducted to evaluate renal function, along with the measurement of oxidative stress and related pathway proteins. The open-field experiments validated the successful establishment of the acute stress model. Acute stress-induced renal injury led to increased NADPH oxidase 4 (NOX4) protein expression and decreased expression levels of nuclear transcription factor 2 (Nrf2), heme oxygenase-1 (HO-1), and NAD(P)H: quinone oxidoreductase 1 (NQO1). Following DEX treatment, there was a significant reduction in renal NOX4 expression. The DEX-treated group exhibited normalized renal biochemical results and less damage observed in pathological sections compared to the acute stress group. The findings suggest that DEX treatment during acute stress can impact the NOX4/Nrf2/HO-1/NQO1 signaling pathway and inhibit oxidative stress, thereby preventing acute stress-induced kidney injury. Additionally, DEX shows promise for clinical applications in stress syndromes.

Vitamin E reduces oxidative stress in brains of male albino male rats undergoing immobilization

Stress can lead to various health problems. Exposure to stress is linked to several diseases including cancer, hypertension, diabetes, mental disorders, and heart attacks. Stress stimulates several pathways that produce free radicals, which increases oxidative stress. This results in functional and structural damage to organs, such as the brain, which is highly sensitive to oxidative stress Vitamin E is a naturally occurring potent antioxidant used for various purposes. The main purpose of the current study was to evaluate how vitamin E protects the brain and to what extent it affects antioxidant levels in rats subjected to two hours per day of immobilization stress, the form of stress with the strongest effect. The rats were immobilized by folding their limbs in and wrapping them in netting to prevent movement, while allowing their tails to be extended. The rats were then hung upside down. The effect of vitamin E was tested by intraperitoneally injecting rats with 40 mg/kg of vitamin E daily. Oxidative stress parameters were determined at the completion of the experiment. A dramatic decrease in malondialdehyde (MDA) levels and an increase in catalase (CAT), including glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), has been shown by vitamin E in the brain. The effects of vitamin E were significantly higher in the acute and chronic stress groups than in the control group. Vitamin E can decrease oxidative stress in stressed rats, indicating that it exerts therapeutic and protective effects owing to its antioxidant properties.

Mice Lacking TAAR1 Show No Early Behavioral Response to Acute Restraint Stress

The role of the TAAR1 receptor, one of the trace amine-associated receptors (TAARs) family, in the formation of the behavioral component of the stress response was studied. The behavior of female TAAR1 knockout mice and wild-type (WT) mice was investigated in tests of elevated plus maze and elevated zero maze (EPM and EZM) and forced swimming test (FST) under normal conditions and after uncontrolled restraint stress exposure for 30 min. In the EPM test, the initial level of locomotor and exploratory activity, as well as the anxiety, was identical in both groups of mice. In the EZM test, the initial indicators of anxiety in female TAAR1 KO mice compared to female WT mice were higher, and locomotor activity was lower. When testing mice in the EZM 30 minutes after the end of stress exposure, it was found that the anxiety in female WT mice sharply increased, and the indicators of locomotor activity and exploratory behavior significantly decreased. The behavioral indicators in the EZM test in TAAR1 KO mice before and after stress were identical. A pronounced behavioral component of the stress response was observed in both TAAR1 KO and WT mice during testing in EPM. There were no significant differences between TAAR1 KO and WT mice during testing in EPM four hours after stress exposure. In the FST test the latency to the first immobility was initially longer in TAAR1 KO mice compared to the WT mice, but 24 h after the stress this indicator has significantly decreased. As a result, TAAR1 KO and WT mice no longer differed in all behavioral indicators in the FST. Three weeks after acute restraint stress, both TAAR1 KO and WT groups showed a significant increase in immobility duration and a decrease in latency to the first immobility, however no difference between the both groups of animals were found. Thereby, we found the complete absence of behavioral change immediately after stressor exposure in TAAR1 KO compared to the WT mice.

Liver Transcriptome Analysis of the Black Porgy (Acanthopagrus schlegelii) under Acute Low-Temperature Stress.

High nutritional value and the development of efficient biotechnological methods of controlled production have made black porgy (Acanthopagrus schlegelii) an economically important fish in Chinese aquaculture in recent years. However, aquaculture production of the species faces multiple issues associated with reduced growth rate, low reproduction ability, and high mortality during production, which are associated with the species' limited tolerance to low temperatures. To date, comprehensive information on the genetic-based mechanisms of cold tolerance and adaptation to low temperature in the species are still unavailable. In this study, the HiSeq™2500 (Illumina) sequencing platform was used to analyze the transcriptomic profile of the liver tissue in the black porgy subjected to different extents of cold shock, including a control temperature group (AS, T = 15 °C), an intermediate temperature group (AL1, T = 10 °C), and an acute low-temperature stress group (AL2, T = 5 °C). For this purpose, three standardized cDNA libraries of AS, AL1, and AL2 were established. We obtained 43,258,908, 48,239,072, and 38,983,833 clean reads from the AS group, AL1 group, and AL2 group, respectively. After pairwise comparison, 70 differentially expressed genes (DEGs) were identified in the examined fish groups. Among them, 60 genes were found to be significantly differentially expressed after trend analysis. GO annotation and enrichment results showed that they were mainly enriched into three categories: biological processes (12 subcategories), molecular functions (7 subcategories), and cellular components (7 subcategories). KEGG analysis results indicated that all significantly differentially expressed genes were annotated to 102 signaling pathways, including biological rhythm, cholesterol metabolism, glycerolipid metabolism, animal autophagy, FoxO signaling pathway, steroid biosynthesis, and regulation of adipocyte lipolysis and apoptosis. Four of them, namely: G6PC, GPX1, GCK, and HSPE1 were randomly selected for further qRT-PCR verification of data reliability obtained by RNA-Seq technology. In this study, we found that environmental acute cold stress mainly affected the black porgy's biological processes related to metabolism, apoptosis, and signal transduction. The data that we have reported provides baseline information for further studies concerning the genetic responses of the black porgy under cold stress conditions, the improvement of its aquaculture production, and other economically important matters regarding their limited tolerance to cold shock.

Chronic stress but not acute stress decreases the seizure threshold in PTZ-induced seizure in mice: role of inflammatory response and oxidative stress.

Seizure is paroxysmal abnormal electrical discharges in the cerebral cortex. Inflammatory pathways and oxidative stress are involved in the pathophysiology of seizures. Stress can induce an oxidative stress state and increase the production of inflammatory mediators in the brain. We investigated the effects of acute and chronic stresses on the seizure threshold in pentylenetetrazol (PTZ)-induced seizures in mice, considering oxidative stress and inflammatory mediators in the prefrontal cortex. In this study, 30 male Naval Medical Research Institute (NMRI) mice were divided into 3 groups, including acute stress, chronic stress, and control groups. PTZ was used for the induction of seizures. The gene expression of inflammatory markers (IL-1β, TNF-α, NLRP3, and iNOS), malondialdehyde (MDA) level, nitrite level, and total antioxidant capacity (TAC) were assessed in the prefrontal cortex and serum. Our results showed that stress could increase the expression of inflammatory cytokines genes and oxidative stress in the prefrontal cortex of the brain and serum following PTZ-induced seizures, which is associated with increased seizure sensitivity and decreased the seizure threshold. The effects of chronic stress were much more significant than acute stress. We concluded that the effects of chronic stress on seizure sensitivity and enhancement of neuroinflammation and oxidative stress are much greater than acute stress.

Integrated biochemical, transcriptomic and metabolomic analyses provide insight into heat stress response in Yangtze sturgeon (Acipenser dabryanus)

Temperature fluctuations caused by climate change and global warming pose a great threat to various species. Most fish are particularly vulnerable to elevated temperatures. Understanding the mechanism of high-temperature tolerance in fish can be beneficial for proposing effective strategies to help fish cope with global warming. In this study, we systematically studied the effects of high temperature on Acipenser dabryanus, an ancient living fossil and flagship species of the Yangtze River, at the histological, biochemical, transcriptomic and metabolomic levels. Intestinal and liver tissues from the control groups (18 °C) and acute heat stress groups (30 °C) of A. dabryanus were sampled for histological observation and liver tissues were assessed for transcriptomic and metabolomic profiling. Histopathological analysis showed that the intestine and liver tissues were damaged after heat stress. The plasma cortisol content and the levels of oxidative stress markers (catalase/glutathione reductase) and two aminotransferases (aspartate aminotransferase/alanine aminotransferase) increased significantly in response to acute heat stress. Transcriptomic and metabolomic methods showed 6707 upregulated and 4189 downregulated genes and 64 upregulated and 78 downregulated metabolites in the heat stress group. Heat shock protein (HSP) genes showed striking changes in expression under heat stress, with 21 genes belonging to the HSP30, HSP40, HSP60, HSP70 and HSP90 families significantly upregulated by short-term heat stress. The majority of genes associated with ubiquitin and various immune-related pathways were also markedly upregulated in the heat stress group. In addition, the combined analysis of metabolites and gene profiles suggested an enhancement of amino acid metabolism and glycometabolism and the suppression of fatty acid metabolism during heat stress, which could be a potential energy conservation strategy for A. dabryanus. To the best of our knowledge, the present study represents the first attempt to reveal the mechanisms of heat stress responses in A. dabryanus, which can provide insights into improved cultivation of fish in response to global warming.

Characterization of pig skeletal muscle transcriptomes in response to low temperature

The response of mammals to cold environment is a complex physiological activity, and its underlying mechanism must be analyzed from multiple perspectives. Skeletal muscle is an important thermogenic tissue that maintains body temperature in mammals. We dissected the molecular mechanism of pig skeletal muscle response to a cold environment by performing comparative transcriptome analysis in the Enshi black pig. Three pigs were subjected to acute cold stress (3 days), three pigs were subjected to cold acclimation (58 days), and three pigs were used as controls. RNA-seq was used to screen the differentially expressed genes (DEGs) of skeletal muscle. Using RNA-seq methods, we identified 1241 DEGs within the acute cold stress group and 1886 DEGs within the cold acclimation group. Prolonged cold exposure induced more gene expression changes. A total of 540 key cold-responsive DEGs were found, and their trends were consistent within the acute cold stress group and cold acclimation group. Gene expression pattern analysis showed that there were significant differences between the low-temperature treatment groups and the control group, and there were also differences between individuals after long-term low-temperature treatment. Analysis of DEGs revealed that 134 pathways were significantly enriched in the cold adaptation group, 98 pathways were significantly enriched in the acute cold stress group, and 71 pathways were shared between the two groups. The 71 shared pathways were mainly related to lipid, amino acid, and carbohydrate metabolism; signal transduction; endocrine, immune, and nervous system; cardiovascular disease; infectious diseases caused by bacteria or viruses; and neurodegenerative disease. In conclusion, this study provides insights into the molecular mechanism of porcine skeletal muscle response under low-temperature environment. The data may assist further research on the mechanism of pig response to cold exposure.

Min pig skeletal muscle response to cold stress.

The increased sensitivity of pigs to ambient temperature is due to today’s intensive farming. Frequent climate disasters increase the pressure on healthy pig farming. Min pigs are an indigenous pig breed in China with desirable cold resistance characteristics, and hence are ideal for obtaining cold-resistant pig breeds. Therefore, it is important to discover the molecular mechanisms that are activated in response to cold stress in the Min pig. Here, we conducted a transcriptomic analysis of the skeletal muscle of Min pigs under chronic low-temperature acclimation (group A) and acute short cold stress (group B). Cold exposure caused more genes to be upregulated. Totals of 125 and 96 differentially expressed genes (DEGs) were generated from groups A and B. Sixteen common upregulated DEGs were screened; these were concentrated in oxidative stress (SRXN1, MAFF), immune and inflammatory responses (ITPKC, AREG, MMP25, FOSL1), the nervous system (RETREG1, GADD45A, RCAN1), lipid metabolism (LRP11, LIPG, ITGA5, AMPD2), solute transport (SLC19A2, SLC28A1, SLCO4A1), and fertility (HBEGF). There were 102 and 73 genes that were specifically differentially expressed in groups A and B, respectively. The altered mRNAs were enriched in immune, endocrine, and cancer pathways. There were 186 and 91 differentially expressed lncRNAs generated from groups A and B. Analysis of the target genes suggested that they may be involved in regulating the MAPK signaling pathway for resistance to cold. The results of this study provide a comprehensive overview of cold exposure–induced transcriptional patterns in skeletal muscle of the Min pig. These results can guide future molecular studies of cold stress response in pigs for improving cold tolerance as a goal in breeding programs.

Acute and Protracted Prenatal Stress Produce Mood Disorder-Like and Ethanol Drinking Behaviors in Male and Female Adult Offspring.

BackgroundAlcohol use disorder (AUD) is a complex and chronic relapsing brain disease, which is often co-morbid with psychiatric disorders such as anxiety and depression. AUD phenotypes differ in men and women. Although genetic factors play an important role in its pathophysiology, epidemiologic evidence suggests that during prenatal development, individuals are more vulnerable to the negative effects of environmental factors that may predispose them to AUD later in life. We explored the effects of prenatal stress on the development of AUD phenotypes as well as anxiety- and depression-like behaviors using rat model.MethodsIn this study, timed-pregnant Sprague Dawley dams were used. Dams in the control group were left undisturbed throughout gestation, whereas dams in stress groups were either subjected to protracted or acute restraint stress under bright light. At adulthood, the anxiety-like, ethanol drinking, and sucrose drinking behaviors were measured using the Light/Dark Box test and two-bottle free-choice procedure.ResultsCompared to the control group, both the male and female offspring in the stress groups exhibited anxiety-like behavior and consumed significantly higher amounts of ethanol in which the acute stress group demonstrated the higher ethanol preference. Moreover, male but not female offspring from the stress groups had decreased sucrose preferences.ConclusionThese findings suggest that protracted and acute prenatal stress in late pregnancy can induce in anxiety-, depressive-like behaviors, and excessive ethanol intake in adult offspring.

Citrullus colocynthis Seed Ameliorates Layer Performance and Immune Response under Acute Oxidative Stress Induced by Paraquat Injection.

Simple SummaryIn recent years, natural, plant-based antioxidants have been increasingly popular among poultry producers to boost production and welfare. Colocynth, i.e., Citrullus colocynthis, is an herbaceous plant known to have antioxidant properties. Employing laying hens, this study investigated the potency of dietary colocynth seed supplementation to reduce the deleterious effects of acute oxidative stress induced by paraquat injection. The results demonstrated that supplementing layers’ diets with colocynth seed at 0.1% alleviated oxidative stress responses and significantly improved egg production performance. Furthermore, the immunological responses of the acute-oxidative-stressed layers were enhanced with colocynth seed supplementation. Thus, the inclusion of colocynth seed in layer chickens’ diets can improve egg production performance, restore the redox balance, and enhance immunological responses when they are reared under acute oxidative stress conditions.Oxidative stress is a detrimental physiological state that threatens birds’ productivity and general health. Colocynth is an herbal plant known for its bioactive properties, and it is mainly known for its antioxidant effects. This study’s purpose was to investigate how effective colocynth seed is at lowering the detrimental impact of acute oxidative stress caused by paraquat (PQ) injection in laying hens. A total of 360 Hy-Line Brown chickens, aged 39 weeks, were gathered and divided into four equal groups (10 hens × 9 replicates) in a 2 × 2 factorial design. The experimental groups were given either a basal diet or the basal diet supplemented with colocynth seed (1% of diet). Starting from week 40 of age and for 7 successive days, the experimental groups were either injected daily with paraquat (5 mg/kg body weight) or with saline (0.5 mL, 0.9% NaCl). Egg production performance with selected stress biomarkers and immunological response parameters were investigated at the end of week 40 of age. Our data revealed a significant reduction in egg production with an increase in blood stress biomarkers (i.e., HSP-70, corticosterone, and H/L ratio) in PQ-injected groups compared with non-stressed groups. Furthermore, an unbalanced redox state was detected in acute oxidative stress groups, with a significant rise in lipid peroxidation level, a reduction in total antioxidant capacity (TAC), and a drop in superoxide dismutase (SOD) and catalase enzyme activity. Supplementing PQ-injected hens with colocynth seed reduced the deleterious effects of acute oxidative stress. There was a significant drop in stress biomarkers with a significant rise in antioxidant enzyme activity and TAC observed in the PQ-injected group provided with colocynth seed supplementation. Remarkably, supplementation of colocynth in the non-stressed group resulted in a significant 27% increase in TAC concentration and 17% higher SOD activity when compared with the non-stressed control group. Colocynth supplementation in the PQ-injected group elevated the total white blood cell count by 25% and improved the B-lymphocyte proliferation index (a 1.3-fold increase) compared with the PQ-injected group that did not receive supplementation. Moreover, the non-stressed colocynth-supplemented group had significantly higher cell-mediated and humoral immune responses than the non-stressed control group. This study demonstrated that colocynth seed supplementation in birds exposed to acute oxidative stress may effectively alleviate its negative impacts on production performance, immunological responses, and redox status. We also inferred that, under normal conditions, colocynth seed can be added to laying hens’ diets to stimulate production and ameliorate immune responses.

Acute heat stress during transportation deteriorated the qualities of rainbow trout (Oncorhynchus mykiss) fillets during chilling storage and its relief attempt by ascorbic acid

The work was to investigate the impacts of acute heat stress during transportation on the tissue structure, physicochemical and microbial qualities of rainbow trout (Oncorhynchus mykiss) fillets during chilling storage and its relief attempt by ascorbic acid. Different transportation groups were performed: transported samples under controlled temperature, T1; transported samples without temperature control, T2; and transported samples with the addition of 30 mg L-1 ascorbic acid, T3. Rainbow trout without transportation were set as the control. In comparison with non-heat stress treatment (control and T1 group), the acute heat stress (T2 and T3 group) significantly increased the relaxation time of free water (T22), total volatile basic nitrogen (TVB-N) and malondialdehyde (MDA) content, total viable count (TVC) and K value of fillets during chilling storage. T3 group had tissue with relative integrity cell shapes and lower expressible moisture (0–3 d), TVB-N and MDA content and TVC (0–7 d) compared with acute heat stress group (T2 group). Therefore, acute heat stress during transportation accelerated the quality deterioration of fillets during the storage, and treatment of control water temperature or the addition of ascorbic acid partially relieved the damage caused by acute heat stress.

Dynamic Variation in Hippocampal Metabolism after Acute Stress Exposure: An In Vivo Proton Magnetic Resonance Spectroscopy Study at 9.4 T

An acute stress response is a complex process that activates the neuroendocrine and metabolic systems for homeostasis. A study on acute stress is important to understand how an organism adapts to stress for survival. However, most studies have focused on chronic stress, and there are few studies on acute stress. They have analyzed the metabolic alterations in the brain at a particular time after acute stress. This study explored the temporal variations of the brain metabolites in the hippocampus after acute restraint stress using proton magnetic resonance spectroscopy. All mice in the acute stress group were physically restrained for two hours in a 50 mL conical tube. A 9.4 T animal MRI and MRS scanner was used with point-resolved spectroscopy technique for data acquisition, which was repeated four times without interscan interval. Metabolites were quantified from the data using LCModel with a simulated basis set. Based on the change in concentration of metabolites, the data were statistically analyzed using two-way repeated-measures analysis of variance between groups and a support vector machine for all time points and Student’s t-test with FDR correction for each time point. The present study found that the differences between groups are significantly ( P < 0.05 ) presented in alanine and glutamate. The effect of time of the two metabolites significantly exists ( P < 0.05 ): the first, second, and third time points in alanine and the first and second time points in glutamate. A combination of stress-specific metabolites (alanine, glutamate, N-acetyl-aspartate) that best reflect the influence of acute stress was determined using a support vector machine. These findings may indicate the importance of the timing of analysis after acute stress and provide new insights into a deeper understanding of acute stress response, including the molecular mechanism of stress-related disorders and stress resilience or vulnerability.

De Novo Transcriptome Analysis Reveals Potential Thermal Adaptation Mechanisms in the Cicada Hyalessa fuscata.

Simple SummaryIn metropolitan Seoul and its vicinity, cicadas of the species Hyalessa fuscata living in warmer areas could tolerate the heat better than those living in cooler areas, but genetic mechanisms involved in better heat tolerance remained unclear. In this study, we examined differences in gene expression of cicadas living in a warm urban area, a cool urban area and a suburban area in three experimental treatments: no heating, 10 min heating and heating until the cicadas lost their mobility. Cicadas from the warm urban area changed their gene expressions the most. Activated genes were mostly related to heat shock, energy metabolism, and detoxification. These results suggested that under heat stress, cicadas inhabiting warm areas could differentially express genes to increase their thermal tolerance. In metropolitan Seoul, populations of the cicada Hyalessa fuscata in hotter urban heat islands (“high UHIs”) exhibit higher thermal tolerance than those in cooler UHIs (“low UHIs”). We hypothesized that heat stress may activate the expression of genes that facilitate greater thermal tolerance in high-UHI cicadas than in those from cooler areas. Differences in the transcriptomes of adult female cicadas from high-UHI, low-UHI, and suburban areas were analyzed at the unheated level, after acute heat stress, and after heat torpor. No noticeable differences in unheated gene expression patterns were observed. After 10 min of acute heat stress, however, low-UHI and suburban cicadas expressed more heat shock protein genes than high-UHI counterparts. More specifically, remarkable changes in the gene expression of cicadas across areas were observed after heat torpor stimulus, as represented by a large number of up- and downregulated genes in the heat torpor groups compared with the 10 min acute heat stress and control groups. High-UHI cicadas expressed the most differentially expressed genes, followed by the low-UHI and suburban cicadas. There was a notable increase in the expression of heat shock, metabolism, and detoxification genes; meanwhile, immune-related, signal transduction, and protein turnover genes were downregulated in high-UHI cicadas versus the other cicada groups. These results suggested that under heat stress, cicadas inhabiting high-UHIs could rapidly express genes related to heat shock, energy metabolism, and detoxification to protect cells from stress-induced damage and to increase their thermal tolerance toward heat stress. The downregulation of apoptosis mechanisms in high-UHI cicadas suggested that there was less cellular damage, which likely contributed to their high tolerance of heat stress.

Changes of L-Arginine Metabolism in Rat`S Colon Mucosa Under the Conditions of COX/LOX Inhibition and Acute Stress Action

Introduction. L-arginine is a semi-essential amino acid and a precursor of many biologically active compounds. Polyamines and NO produced from L-arginine take part in the regulation of biochemical processes in colon mucosa. Emotional stress, nonsteroidal anti-inflammatory drugs (NSAIDs) and their combined action can change the activity of L-arginine metabolizing enzymes. The aim of this study was to investigate the single action of NSAIDs with different mechanisms of action and their combination with acute stress on L-arginine metabolism in colon mucosa of rats. Methods. Animals were divided into 8 groups: control group (1), administration of nonselective, COX-2 selective and dual COX-2/5-LOX inhibitors (groups 2-4), acute stress group (5), administration of same NSAIDs as in groups 2-4 under the conditions of acute stress (groups 6-8). The activity of iNOS, cNOS, arginase, concentration of L-arginine, nitrite and nitrate was measured in colon mucosa. Results. Nonselective COX inhibition by naproxen caused the increase in iNOS and decrease in cNOS activity in colon mucosa. Both COX-2 (celecoxib) and dual COX-2/5-LOX (2A5DHT) inhibitors enhanced cNOS and arginase acting in combination with acute stress. The concentration of L-arginine remained unchanged in most of the groups, but combination of dual COX-2/5-LOX inhibitor and acute stress raised this parameter.

Progenitor Stem Cells Behavior in the Adrenal Gland of Acute-Stress Albino Rat Model: A Histological and Immunohistochemical Study

Background: The adrenal gland achieves a greater degree of plasticity in response to stress. This is attained through the proliferation and differentiation of the adult adrenal progenitors. Aim of the work: This work aimed to assess the presence of adrenal progenitor cells and their behavior under acute stress and recovery. Material and methods: Eighteen male rats (8 weeks, 200-250g) were equally divided into three groups: Control rats, Acute-Stress rats were exposed to restraint stress for 2 h without food and water during the stress period, recovered rats were exposed to the same pattern of stress, then housed in enriched environment supplied with running wheel for six days. After scarification, the blood samples were collected for plasma cortisol assessment, the glands were excised and processed for histological and immunohistochemical studies. Result: The cortisol level was elevated in the acute-stress group, but returned to normal level in the recovered group. The adrenal glands of the acute-stress group showed vacuolations, congestion, and hemorrhage, however, the recovered group showed improvement in the gland histology. Both Nestin and GFAP expressions were detected mainly in the capsular and subcapsular regions and medulla of all groups. The expression chromogranin-A was markedly increased in both acute-stress and recovered groups as compared to the control group, and it was greatly higher in the acute-stress group as compared to the recovered group indicated increased chromaffin cell number. Conclusion: In acute stress, Nestin progenitor cells of the adrenal gland were capable of differentiation into chromogranin-A expressing chromaffin cells

Hepatic acute-phase response, antioxidant biomarkers and DNA fragmentation of two rabbit breeds subjected to acute heat stress

Acute heat stress (AHS) is known to affect rabbit production and well-being negatively. Yet, early acute heat stress effect on later physiological response is poorly studied. Our study aimed to provide more knowledge of rabbit physiological response to early acute heat stress in two distinguished rabbit breeds. A total of 120 males of New Zealand White (NZW) and Baladi Black (BB) rabbits five weeks old were recruited and randomly divided into two sub-groups, control groups (Control) reared in a controlled environmental chamber 28 °C, and 40% RH and early acute heat stress groups (HS) exposed to 36 °C and 62% RH for 6 hours. At 13 weeks, rabbits of all groups were subjected to the same AHS conditions. Our results, irrespective of breeding differences, demonstrate a significant (p < .05) increase in inflammation markers (TNFα, IL-6 and lipid peroxidation), acute-phase proteins (ceruloplasmin, α-1-acid glycoprotein), and DNA fragmentation with a significant reduction in liver antioxidant enzymes concentrations (glutathione reduced, superoxide dismutase, and catalase) in HS groups compared to breed relative control groups. Furthermore, when all experimental groups at 13 weeks of age were subjected to the same stress conditions, the early HS group showed the same significant adverse physiological effects. It can be suggested that rabbits from different genetic groups are vulnerable to acute heat stress exposure at the early stage of life compared to later stages. Highlights Heat stress is one of the most critical issues facing rabbit production. Exposure young rabbits to acute heat stress had adverse effects on physiological parameters in later life. Rabbits exposed to acute heat stress at an early age did not produce thermo-tolerance ability to later time heat exposure.

Comparative analysis of acute and chronic stress-induced neurobehavioral alteration and liver injury in mice

Recent research has shown that stress has a significant influence on the functions of many organs. The present study investigated the effect of acute or chronic restraint stress on physiological and psychological processes. In the acute stress group, body weight and food intake did not change, but in the chronic stress group, food intake significantly increased and body weight was significantly inhibited. ALT and AST levels were significantly increased by both groups. Acute and chronic restraint stress led to different behavioral changes. Serum levels of corticosterone and cortisol were more increased in chronic stress than in acute stress. The levels of neurons and astrocyte in the hippocampus, and the NeuN-positive neuronal cells remained unaffected by acute stress, but were decreased by chronic stress. GFAP-positive astrocytes were increased by both groups. In summary, our study provides evidence of a relationship between liver injury and behavioral change upon exposure to restraint stress.

Environmental enrichment modulates inflammation during development in long-evans rats (Rattus norvegicus).

It is unknown whether increased production of pro-inflammatory mediators during the life span is caused by aging per se or via the combination of a cumulative allostatic load due to life challenges. This study aimed to investigate the long-term effects of stress and environmental enrichment on the inflammatory status associated with aging in rats. Animals were assigned to the following five treatment groups: chronic stress with and without environmental enrichment; acute stress with and without environmental enrichment; control animals. Enrichment was provided as an open field containing novel objects (30min three times per week). Animals assigned to chronic stress groups were exposed to predator sound stressors (e.g., hawk sound) for 30min daily, while animals assigned to acute stress groups were exposed once a week for 30min. The interaction between the hypothalamic-pituitary-adrenal axis and the immune system was investigated by measuring metabolized dehydroepiandrosterone (DHEA) levels and peripheral levels of the cytokines IL-6 and IL-10. Results suggested that inflamm-aging was more pronounced in animals with low DHEA levels, which in turn were affected by exposure to environmental enrichment and acute stress. This study showed that environmental enrichment and acute stress can significantly attenuate disruptions in DHEA production, consequently contributing to improved neuroimmune function of aging animals.

Acute and chronic stress differently alter the expression of cytokine and neuronal markers genes in zebrafish brain

We report the effects of acute and chronic stress on the expression of selective immune-related genes and markers of neuronal function in the brain of the zebrafish (Danio rerio). Fish were distributed into three groups: the non-stressed control group; the acute stress (AS) group, submitted to a single stressing episode; and the unpredictable chronic stress (UCS) group, submitted to two daily stressing episodes of alternating times and types of stress. The stressing protocols were applied for a period of 14 days. The UCS protocol triggered the expression of the pro-inflammatory cytokine genes IL-1β and TNF-α, the anti-inflammatory cytokine IL-10 (negative feedback from the immune system), reduction in cFOS gene expression, and caused neuro-inflammation. The AS protocol had no effect on gene expression. Altered expression of cytokine genes, as observed in our study, correlates with several pathologies associated with neuro-inflammation, and the reduction of cFOS gene expression may indicate the occurrence of reduced neuronal plasticity. Our study further extends our knowledge about the interaction of the immune system and the different forms of stress.

Identification, functional prediction, and key lncRNA verification of cold stress-related lncRNAs in rats liver

Cold stimulation reduces the quality of animal products and increases animal mortality, causing huge losses to the livestock industry in cold regions. Long non-coding RNAs (lncRNAs) take part in many biological processes through transcriptional regulation, intracellular material transport, and chromosome remodeling. Although cold stress-related lncRNAs have been reported in plants, no research is available on the characteristic and functional analysis of lncRNAs after cold stress in rats. Here, we built a cold stress animal model firstly. Six SPF male Wistar rats were randomly divided to the acute cold stress group (4 °C, 12 h) and the normal group (24 °C, 12 h). lncRNA libraries were constructed by high-throughput sequencing (HTS) using rat livers. 2,120 new lncRNAs and 273 differentially expressed (DE) lncRNAs were identified in low temperature environments. The target genes of DElncRNA were predicted by cis and trans, and then functional and pathway analysis were performed to them. GO and KEGG analysis revealed that lncRNA targets were mainly participated in the regulation of nucleic acid binding, cold stimulation reaction, metabolic process, immune system processes, PI3K-Akt signaling pathway and pathways in cancer. Next, a interaction network between lncRNA and its targets was constructed. To further reveal the mechanism of cold stress, DElncRNA and DEmRNA were extracted to reconstruct a co-expression sub-network. We found the key lncRNA MSTRG.80946.2 in sub-network. Functional analysis of key lncRNA targets showed that targets were significantly enriched in fatty acid metabolism, the PI3K-Akt signaling pathway and pathways in cancer under cold stress. qRT-PCR confirmed the sequencing results. Finally, hub lncRNA MSTRG.80946.2 was characterized, and verified its relationship with related mRNAs by antisense oligonucleotide (ASO) interference and qRT-PCR. Results confirmed the accuracy of our analysis. To sum up, our work was the first to perform detailed characterization and functional analysis of cold stress-related lncRNAs in rats liver. lncRNAs played crucial roles in energy metabolism, growth and development, immunity and reproductive performance in cold stressed rats. The MSTRG.80946.2 was verified by network and experiments to be a key functional lncRNA under cold stress, regulating ACP1, TSPY1 and Tsn.